Today, April 20th (4/20 or 420), is marjuana’s high holiday for the eight states and the District of Columbia that now allow recreational use of marijuana, and 30+ states that allow its use for medical purposes. There is even talk from Democrats about introducing a bill in Washington to remove marijuana from the federal list of controlled substances. But today, cannabis is still a controlled illegal substance at the Federal level, it is still illegal to transport cannabis products across state lines, still produces effects on driving that can lead to a DUI or DUID arrest, and it still incredibly difficult to standardize for safety and quality controls. Cannabis is the most phyto-chemically complex plant on the planet. It is an impossible task trying to ensure all plants, even of the same cannabis genotype, have all the same chemical profile.

Some might make the comparison between alcohol prohibition and cannabis, both Federal legislative measures prohibiting the production, importation, transportation and sale of related products on a national level. History has shown that lifting alcohol prohibition has not eliminated the abuse – and resulting consequences – that leads to impaired driving. According to the NHTSA, in 2016 there were 10,497 fatalities in motor vehicle traffic crashes involving drivers with blood alcohol concentration of .08 g/dL, the minimum legal limit for DUI nationwide for adults over 21. According to data from the National Highway Traffic Safety Administration’s Fatality Analysis Reporting System, the number of drivers involved in fatal crashes testing positive for marijuana rose 88 percent from 2013 to 2015. A Denver Post analysis of data and coroner briefings report the number of drivers involved in fatal crashes in Colorado who tested positive for marijuana had risen sharply each year since 2013, more than doubling in that time; state law, however, does not require coroners to test deceased drivers specifically for marijuana use in fatal crashes.

Starting with Oregon in 1973, individual states began to liberalize cannabis laws through decriminalization. In 1996, California became the first state to legalize medical cannabis, sparking a trend that spread to over 30 states by 2017. In 2012, Colorado and Washington became the first states to legalize cannabis for recreational use. Have roads in these states become more dangerous since the drug’s legalization in its various forms? The Post’s findings include:

Marijuana is figuring into more fatal crashes overall. In 2013, drivers tested positive for the drug in about 10 percent of all fatal crashes. By 2016, it was 20 percent.

More drivers are testing positive for marijuana and nothing else. Of the drivers involved in fatal crashes in 2014 who tested positive for cannabinoids, more than 52 percent had no alcohol in their system. By 2016, it had grown to 69 percent.

The average age of drivers in deadly crashes in 2015 who tested positive for marijuana was nearly 35, with a quarter of them over 40.

In 2016, of the 115 drivers in fatal wrecks who tested positive for marijuana use, 71 were found to have Delta-9 tetrahydrocannabinol, or THC, the psychoactive ingredient in marijuana, in their blood, indicating use within hours, according to state data. Of those, 63 percent were over 5 nanograms per milliliter, the state’s limit for driving.

Both alcohol and marijuana can affect a driver’s ability to think and solve problems, coordination, reaction time, judgment, memory and mood. While science has figured out just exactly how alcohol impacts the body’s organs, systems and functions, the same cannot be said of cannabis. Results of field sobriety tests, including blood and urine sampling as well as breathalyzers, can tell if a driver’s blood alcohol level is over the legal limit. No test can tell whether a driver is too high to drive because of smoking or inhaling, popping pills, eating or vaporizing cannabis products. Unlike alcohol, the active ingredients that cause the cannabis high can remain detectable in the blood stream for days or weeks; unlike alcohol, the impairment does not wears off in a matter of hours, and no amount of food intake will change the effects. Law enforcement officials, prosecutors and public policy makers concede there’s still too little information about marijuana and how it is detected to understand just how much the drug is affecting traffic fatalities.